A randomized crossover single-case series comparing blocked versus random treatment for anomia.

The motor learning literature has demonstrated that blocked practice facilitates better acquisition of motor skills, whereas random practice facilitates retention and transfer. The verbal learning and memory literature offers similar evidence. The purpose of this study was to investigate effects of blocked versus random practice in treatment for anomia. The study used a single site, randomized crossover design, with two replicated experimental phases (two blocked and two random) for each of 10 individuals with anomia. Each phase consisted of a cued picture-naming treatment. Individual treatment and maintenance effects, as well as weighted averages and group effects, were calculated using Tau-U based on the proportion of correctly named probes. Nine of 10 participants demonstrated treatment effects during each of the four phases. Acquisition was comparable for blocked and random practice. Maintenance effects were observed following seven blocked phases of treatment and 12 random phases of treatment across participants. For four of 10 participants the random schedule resulted in better maintenance of trained items. Although further research is needed, the present data suggest that for word retrieval treatment with multiple repetitions of the same items, a random presentation may benefit maintenance of treatment gains.